diff --git a/src/app/components/calibrate/calibrate.component.html b/src/app/components/calibrate/calibrate.component.html
index eaef758..4264e0d 100644
--- a/src/app/components/calibrate/calibrate.component.html
+++ b/src/app/components/calibrate/calibrate.component.html
@@ -20,7 +20,7 @@
             </div>
         </div>
         <div>
-            <mat-slider class="w-100" [max]="180" [min]="-180" [step]="1" [tickInterval]="90" [thumbLabel]="true" [(ngModel)]="calibration" (input)="calibration = $event.value"></mat-slider>
+            <mat-slider class="w-100" [max]="180" [min]="-180" [step]="1" [tickInterval]="90" [thumbLabel]="true" [ngModel]="calibration" (input)="calibration = $event.value"></mat-slider>
         </div>
     </div>
     <mat-divider class="mb-1"></mat-divider>
diff --git a/src/app/components/calibrate/calibrate.component.ts b/src/app/components/calibrate/calibrate.component.ts
index e2f09ba..0cd5eda 100644
--- a/src/app/components/calibrate/calibrate.component.ts
+++ b/src/app/components/calibrate/calibrate.component.ts
@@ -27,9 +27,9 @@ export class CalibrateComponent {
     setN() {
         let currentHeading = Math.round(this.physicsService.orientation.value.alpha);
         if(currentHeading > 0) {
-            this.calibration = -currentHeading;
+            this.calibration = currentHeading;
         } else {
-            this.calibration = 360 - currentHeading;
+            this.calibration = -currentHeading;
         }
     }
 }
diff --git a/src/app/services/physics.service.ts b/src/app/services/physics.service.ts
index 0219b9b..68152f8 100644
--- a/src/app/services/physics.service.ts
+++ b/src/app/services/physics.service.ts
@@ -52,7 +52,7 @@ export class PhysicsService {
                             this.requireCalibration.emit();
                         }
 
-                        info.heading = -(data[1] ? data[1].alpha : 0) - (data[2] == Infinity ? 0 : data[2]);
+                        info.heading = -(data[1] ? data[1].alpha : 0) + (data[2] == Infinity ? 0 : data[2]);
                         if(info.heading < 0) info.heading += 360;
                         if(info.heading >= 360) info.heading -= 360;
                     }